UV erase times for 1227730 Memcal?

[EagleMark]

Does anyone remember UV eraseing chips? :laugh:

No I'm not kidding, I'm trying to help a guy in Iran who wants to write a new bin file for his 1990 Olds Cutlass that is open loop Export car. There are a bunch of them over there that collage students were allowed to import and buy back then. Since he is in Iran he can not buy anything from internet, nor have anything shipped to him.

He is a real GearHead and they want to make these cars closed loop for better fuel milage. He has made his own header for reading the Memcal, has a professional computer freind that can UV erase and they have a programmer. But if he destoys the chip? There is no way to get a replacement, or he would have already got the adapters and chip from Moates.

[Tunedperformance]

I still uv erase for a guy in australia with gm tpi maf and 730 sd memcals. what eprom does that he use? I have several 27c256 and 2732a and a few 27c128's. me most I have uv erased is four times. I don't like to do it much because it slows down the eprom. I don't know the exact time you can uv erase a eprom it may very on type and eprom age.

[Tunedperformance]

I help a guy a while back with a export in sweden. I cant recall the bcc thinking it was a 87-88 tpi camaro that never had a oxygen sensor. crazy they did that. not too hard for him to install one and run the wire and get it to go to closed loop. I can't believe they did this to save a couple bucks.

[EagleMark]

Actually the Export open loop, no O2 sensor is because gasoline in other countries like Iraq, Iran, Russia etc... still have lead. Lead severely limits O2 life span. Innovate states in their LC-1 WideBand O2 sensor which can be used with race fuel that life expectancy is 50 to 500 hours. Way below the 100k we can get out of unleaded fuel on an O2 sensor.

One strange story of a guy I helped in Dubai with a 1995 Chevy Impala SS LT1 export was it came with no catalytic converters, but still had heated O2 sensors on each side, but bin was open loop. So that did not even save money as the O2 sensors were still in the car.

But the other one I am helping a guy in Iran with, had no O2 sensor, but the bung was welded on exhaust pipe... not drilled? He just drilled the hole and installed an O2 sensor. But bin is open loop. He did find a closed loop memcal but not correct for his car and data logged to find closed loop was working so the ECM is capable.

Another guy found a bin here on this site for 1227747 that ended up being an export and although he found things in bin to diable closed loop by increasing temp, never could get it to go closed loop. Something in bin beyound what is shown in XDF was changed. He changed to a known closed loop bin and worked right away.

My old UV eraser is set to 8 minutes years ago for 2732a chips I have used it recently at same settings. Don't think I ever tried more then 4 times per chip but worked well with ST chips not stock GM which I think are AMD? I would like to see this guy in Iran succeed in his quest without ruining his memcal.

[Tunedperformance]

Interesting ,I usually find 5-8 min to erase sometimes up to 10 for a 27c256. you should ask rbob lol

[1project2many]

My eraser timer goes off at 3 minutes 43 seconds. If the chip isn't programmable I cycle it again. I've only needed three cycles on a handful of chips and I can't remember the last time I killed a chip by erasing. I've noticed the chips placed near the ends of the bulb don't erase as fast. My PP2 programming software lets me check whether the chip can be reprogrammed, vs blank, which means any bits which need to be set at 1 are already there. It can save a bunch of time as well as wear and tear on the chip.

If he's working with an OE chip then it's a gamble whether or not it will reprogram. Look over all the #'s on the chip, then search through gmecm archives and all over the 'net looking for more information. Programming is the real issue. If the exact chip programming voltage is unknown, advise beginning with lowest programming voltage available. Also, I always start with the "C" version of a chip before moving to an "A" or a "no suffix." I.E. 27C32 then 2732A then 2732 Any opportunity to scrounge through old electronics to find usable Eproms?

[EagleMark]

It's either:






EPROM type:
27C128 or 27C256